[Purification and cytotoxicity of glycoprotein isolated from Dendrobium huoshanense]

Dendrobium huoshanense is a rare traditional Chinese medicinal herb, and the anti-tumor activity of its polysaccharides is a research hotspot in traditional Chinese medicine resources domain. This study aims to explore the material basis for the anti-tumor activity of polysaccharide. D. huoshanense was used as raw material in the experiment, and the different protein components were obtained through low salt solution extraction and ammonium sulfate fractional precipitation. Then glycoprotein components were determined by SDS-PAGE electrophoresis staining, and were further isolated and purified by DEAE ion column and Sephadex gel column. At the same time, MTT assay was used in detecting the cytotoxicity of different products on HepG2 cells in vitro. As a result, three kinds of glycoprotein components RG1, RG2, RG3 with relative molecular mass of 22.5, 19.8, 15.6 kDa were gained, and the IC₅₀ of three compounds on human liver cancer cell HepG2 was 534.23 mg•L⁻¹, meanwhile IC₅₀ of single glycoprotein component RG1, RG2 was 432.96, 413.91 mg•L⁻¹ respectively, and glycoprotein component RG3 had no cytotoxicity on HepG2 cells. All in all, the experiment results suggested that two kinds of glycoproteins components with relative molecular mass of 22.5, 19.8 kDa may be one of the material basis for anti-tumor activity of D. huoshanense polysaccharide, and they had a synergistic effect.